This invention relates generally to a method and system for using touch-sensitive screens, and more specifically, for enabling visually impaired users to use touch-sensitive screens to control various devices.
The modern workplace has become increasingly dependent on electronic devices, such as copy and facsimile machines. Many of these devices have embedded computers to control the functioning of the electronic device. These computers often utilize touch-sensitive screens to input and output information.
A touch-sensitive screen is a display device through which a computer can, in addition to displaying information, receive information by sensing a user""s touch on the touch-sensitive screen. The computer generally displays various objects, such as an icon or a control, on the touch-sensitive screen. These objects typically represent the state of the electronic device and commands that can be performed by the electronic device. For example, an icon representing a selected file may indicate that the file is currently selected to be transmitted by a facsimile machine, and a button, which is a type of control, may represent the command to start sending a document. A user selects an object by touching the displayed object typically with a finger. The computer determines which object is selected by determining which object is displayed at the location the user touched. By selecting an object, the user indicates to the computer that an associated command should be performed. For example, when a xe2x80x9cstartxe2x80x9d button is selected by a user, then a document is sent and when an item in a list is selected, then the item may be highlighted.
FIG. 1 illustrates a conventional touch-sensitive screen 101 for a copy machine. The touch-sensitive screen displays a message area 104 that displays instructions for operation of the device, such as instructing the user to xe2x80x9cEnter Number of Copies.xe2x80x9d The touch-sensitive screen displays a text box 114 which displays the number of copies to be made. The touch-sensitive screen also displays several controls. The controls shown are buttons 106, 108, 110, and 112, and input controls 116 of the numeric pad. Each of the buttons represents a command to be performed by the copy machine. For example, when a user selects the xe2x80x9cClear Number of Copiesxe2x80x9d button 106, then the copy machine enters zeroes into the text box 104. Also, when the user selects the xe2x80x9cstartxe2x80x9d button 108, then the copy machine starts copying.
An electronic device may also display a list box on a touch-sensitive screen. FIG. 2 illustrates a sample list box. A list box allows a user to view a list consisting of list items. If the list contains more list items than can be displayed in the list box at one time, then the user can xe2x80x9cscrollxe2x80x9d through the list using a scroll bar. A user controls scrolling by touching the scroll bar and controls selecting a list item by touching the list item. For example, the list in FIG. 2 contains the list items xe2x80x9cPaper Tray Selectionxe2x80x9d 202 and xe2x80x9cEnlargement Selectionxe2x80x9d 204. By touching the list item xe2x80x9cPaper Tray Selection,xe2x80x9d the user selects this list item. Typically, the list item is then highlighted to provide a visual cue to the user that the list item has been selected. A user may deselect the list item by touching the list item again. A user scrolls through the list by using the scroll bar 212. The scroll bar has a scroll up arrow 206, a scroll down arrow 208, and a scroll thumb 210 (which is also called a scroll box). When a user touches the scroll up arrow, the list typically scrolls up one list item, and when a user touches the scroll down arrow, the list typically scrolls down one list item. In addition, a user may touch the scroll thumb, and while maintaining contact with the touch-sensitive screen, slide the scroll thumb along the scroll bar to scroll through the list. If the user does not maintain contact with the scroll thumb, then scrolling stops.
Because a user needs to see a touch-sensitive screen to use it, conventional touch-sensitive screens on electronic devices make the devices virtually inaccessible for visually impaired users. A touch-sensitive screen displays text, which a visually impaired user may not be able to read. In addition, the flat touch-sensitive screen has no physically raised buttons for a visually impaired user to feel. Instead, touch-sensitive screens utilize a graphical symbol to represent a button, so a visually impaired user may not be able to find buttons on a touch-sensitive screen. In addition, a visually impaired user has difficulty selecting list items or scrolling through the list. Using the scroll bar is especially difficult because it requires the user to not only find the scroll thumb but also maintain contact with the scroll thumb to scroll a list, which the visually impaired user may not even be able to see.
Also, many touch-sensitive screens display text and graphical symbols in low contrast relative to the background color of the touch-sensitive screen which makes the use of a touch-sensitive screen challenging even to users who have limited sight. Moreover, different devices typically display text, icons and controls at different locations on their touch-sensitive screens. For instance, one device may place buttons at the top of the touch-sensitive screen and another may place them at the right side of the touch-sensitive screen. Because of the number and variety of these differences, it is not easy for a user who is visually impaired to memorize these differences and thus use these devices. In addition, a single-touch sensitive screen typically displays different text and graphical symbols depending on context, which makes it difficult for a user who is visually impaired to memorize the differences even on a single touch-sensitive screen.
The community of visually impaired users is large, including users who may have limited vision as well as users who have lost all vision. Because of widespread use of touch-sensitive screens on electronic devices in the workplace, visually impaired users are finding it increasingly difficult to find or maintain employment in positions that require use of these electronic devices. In addition, the use of touch-sensitive screens has expanded into areas outside the workplace. For example, touch-sensitive screens are used on microwave ovens and in computerized information guides at airports. As the use of touch-sensitive screens increases, visually impaired users find more devices to be inaccessible to them.
It is an object of the present invention to enable a visually impaired user to explore the objects on a touch-sensitive screen.
It is another object of the present invention to enable a visually impaired user to select controls displayed on a touch-sensitive screen.
It is yet another object of the present invention to enable a visually impaired user to scroll through lists on a touch-sensitive screen by sliding a scroll thumb.
These and other objects, which will become apparent as the invention is more fully described below, are obtained by the interface for the visually impaired (IVI) system. In a preferred embodiment, the IVI system provides a method for selecting a control region that is displayed on a touch-sensitive screen. The touch-sensitive screen has regions, including control regions. Each control region is associated with a command. The IVI system determines whether a user is contacting the touch-sensitive screen over a control region. When the user is contacting the touch-sensitive screen over a control region, the IVI system determines whether the user has terminated contact with the touch-sensitive panel without contacting the touch-sensitive screen outside of the control region. When the user has terminated contact with the touch-sensitive screen, the IVI system selects the control region and performs the command. The IVI system uses a similar method for selecting items in a list.
Another aspect of a preferred embodiment of the IVI system provides a method of scrolling through a list of list items. The IVI system defines a scroll bar region with a scroll box for a touch-sensitive screen. The IVI system determines whether the user is contacting the scroll box. If the user is contacting the scroll box, the IVI system determines the initial position of the scroll box. Then, the IVI system determines whether the user, without contacting the touch-sensitive screen outside of the scroll box, subsequently terminates contact with the touch-sensitive screen. When the user terminates contact with the touch-sensitive screen in such a manner, the IVI system enters a scroll mode. When the user again touches the touch-sensitive screen, the IVI system then scrolls the list based on position of contact with the touch-sensitive screen. In addition, in a preferred embodiment, the IVI system provides audio feedback as to what object a user is touching and as to the number of list items that have been scrolled.